iOS under symbol not found: ___sincosf_stret error

In debugging a multimedia application with a third-party library, it is found that the iOS6.1.2 version must be crash, showing symbol not found: ___sincosf_stret error, this error is rare.

As shown, from the hint, there was an error in delaying the binding of the symbol table, and no ___sincosf_stret was found. And then very thoughtful hint libsystem.b.dylib this dynamic library, because did not join libsystem.b.dylib this dynamic library, the first reaction is to join this dynamic library. Compile and run without slightest change.

Carefully think, indeed there is no reason, this hint a bit inexplicable, so the internet search, found someone in iOS with OPENCV, also encountered a similar problem, someone Huitie said change command line tool, Dead Horse when live horse medicine tried, the problem as usual. But this post is older, when Xcode5 just came out, or DP version of the time things, the main reason is not the compiler option, but the third-party library compatibility, which gave me a thought, will I also be a third-party library compatibility problem?

Then I tried to run on the iOS7, and sure enough, it was normal to run, which means it really had something to do with the SDK because the third-party library was compiled from the 7.1 SDK.

This problem is due to the fact that the deploy of target error on iOS7 is on a lower version, and updating the third-party library solves the problem

Debugging in the face of strange problems is to be more observation, careful analysis, but also need to look at other people's practice.

iOS under symbol not found: ___sincosf_stret error